Method and device or dividing plate-like member

ABSTRACT

In a method and an apparatus for dividing a plate-like member related to the present invention, multiple substrates are obtained by forming a linear modified region on a surface of a plate-like member formed from a hard and brittle material or in the interior of the plate-like member and dividing the plate-like member along this modified region. The method for dividing a plate-like member includes a tape sticking step which involves sticking tape on the surface of the plate-like member, a modified region forming step which involves forming a modified region on surface of the plate-like member or in the interior of the plate-like member, and an expanding step which involves elongating the tape by applying a tension thereto after the modified region forming step. In the expanding step, the tape is irradiated with UV rays. As a result of this, it is possible to positively manufacture an ultrathin chip with a good end-face shape in which uncut portions, chipping and breakage do not occur.

TECHNICAL FIELD

The present invention relates to a method and an apparatus for dividinga plate-like member from which chips for semiconductor devices,electronic parts and the like are manufactured and, more particularly,to a method and an apparatus for dividing a plate-like member which aresuitable for working a wafer to a prescribed thickness by grinding theback surface of the wafer and thereafter performing working for forminga modified region by laser beams and dividing the wafer into individualchips.

BACKGROUND ART

In recent years, ultrathin IC chips which are built in ultrathin ICcards and the like represented by a smart card have been required. Suchultrathin IC chips are manufactured by dividing an ultrathin wafer ofnot more than 100 μm into individual chips.

Against this background, in conventional methods for dividing aplate-like member for semiconductor devices, electronic parts and thelike, as shown in the flowchart of FIG. 7, a protective tape stickingstep (Step S101) is first performed. In this protective tape stickingstep, in order to protect a wafer surface on which may semiconductordevices, electronic parts and the like are formed, a protective tapehaving an adhesive on its one side is first stuck to a wafer surface.Subsequently, a back surface grinding step (Step S103) is performed. Inthis back surface grinding step, the wafer is ground from its backsurface and worked to a prescribed thickness.

After the back surface grinding step, a frame mounting step is performedwhich involves mounting the wafer on a dicing frame by use of a dicingtape having an adhesive on its one surface and the wafer and the dicingtape become integrated (Step S105). Subsequently, a protective taperemoving step is performed which involves adsorbing the wafer in thiscondition on the dicing tape side and removing the protective tape stuckto the surface (Step S107).

The wafer from which the protective tape has been removed, along withthe frame, is transferred to a dicing saw and cut into individual chipsby a diamond blade which rotates at a high speed (Step S109).Subsequently, in the expanding step the dicing tape is radiallyelongated and the intervals between individual chips are widened (StepS111), and in the chip mounting step the chips are mounted on packagesubstrates such as lead frames (Step S113).

However, in such conventional methods for dividing a plate-like member,it was necessary to use a protective tape for preventing the pollutionof a wafer surface during the grinding of the back surface of the waferand a dicing tape for holding chips after dicing and this lead to anincrease in the cost of consumables.

Furthermore, in the case of an ultrathin wafer having a thickness of notmore than 100 μm, under conventional methods by which a wafer is cut byuse of a dicing saw, chipping and breakage are formed during cutting,thereby posing the problem that good chips become defective products.

As means to solve the problem that chippings and breakage occur in awafer during cutting, there have been proposed techniques related to alaser processing method which involves, in place of conventional cuttingby a dicing saw, causing laser beams to become incident, with acondensing point aligned in the interior of a wafer, forming a modifiedregion in the interior of the wafer by multiphoton absorption, and thendividing the wafer into individual chips (refer to, for example, theJapanese Patent Laid-Open No. 2002-192367, the Japanese Patent Laid-OpenNo. 2002-192368, the Japanese Patent Laid-Open No. 2002-192369, theJapanese Patent Laid-Open No. 2002-192370, the Japanese Patent Laid-OpenNo. 2002-192371, and the Japanese Patent Laid-Open No.2002-205180).

However, in the techniques proposed in the above-cited unexamined patentpublications, a dicing device by a dividing technique by use of laserbeams is proposed in place of a conventional dicing device by a dicingsaw, and although the problem that chippings and breakage occur in awafer during cutting is solved, the problem that in the expanding step,portions which are not divided are formed and end-face shapes of dividedchips become poor.

FIGS. 8 and 9 are each a conceptual figure to explain this phenomenon.In FIG. 8, a dicing tape S is stuck to the back surface of a wafer W andthe peripheral edge portion of the dicing tape S is fixed to a frame F.A modified region K in rectangular arrangement is formed in the wafer Wby laser beams. Subsequently, in the expanding step, the dicing tape Sis elongated, with the result that the wafer W is divided into multiplechips T, with the modified region serving as starting points.

The elongating of the dicing tape S in the expanding step is performed,for example, by pushing up a cylindrical ring member from below in anannular portion between the frame F of the dicing tape S and the waferW.

FIG. 9 is a schematic diagram to explain the division of a wafer W in anexpanding step. FIG. 9(a) is a plan view and FIG. 9(b) is a sectionalview. As shown in FIG. 9(b), a modified region K formed by laser beamsis present in the interior of the wafer W. As shown in FIG. 9(a),cutting is performed satisfactorily when a uniform tension is applied tothe wafer W.

In conventional methods and apparatus for dividing a plate-like member,however, it is often that in the expanding step, the elongation of thedicing tape S does not become uniform all over the surface of the waferW. For example, the dicing tape S in a portion where cutting has alreadybeen performed is locally elongated, and it becomes impossible to applya tension to the dicing tape S in uncut portions. As a result, it isoften that uncut portions are formed and that the end-face shapes ofdivided chips do not become linear and become poor.

The present invention has been made in view of such circumstances andhas as its object the provision of a method and an apparatus fordividing a plate-like member which can positively manufacture anultrathin chip with a good end-face shape in which uncut portions,chippings and breakage do not occur when, after working a wafer to aprescribed thickness by grinding the back surface of the wafer, workingfor forming a modified region by laser beams is performed and the waferis divided into individual chips.

Also, the present invention has as its another object the provision of amethod and an apparatus for dividing a plate-like member which canminiaturize the apparatus for dividing a plate-like member and canperform dividing work of a plate-like member in a short time.

DISCLOSURE OF THE INVENTION

To achieve the above-described objects, the present invention provides amethod for dividing a plate-like member formed from a hard and brittlematerial, which comprises a tape sticking step which involves stickingtape on a surface of the plate-like member, a modified region formingstep which involves forming a linear modified region on the surface ofthe plate-like member to which the tape has been stuck or in theinterior thereof, and an expanding step which involves elongating thetape by applying a tension thereto after the modified region formingstep and irradiating the tape with UV rays, whereby the plate-likemember is divided along the linear modified region thereby to obtainmultiple substrates.

Also, to achieve the above-described objects, the present inventionprovides an apparatus for dividing a plate-like member which is formedfrom a hard and brittle material and to the surface of which tape isstuck and a liner modified region is formed on the surface of which orin the interior of which along the modified region to obtain severalsubstrates. The apparatus comprises expanding means which applies atension to the tape and elongates the tape in order to divide theplate-like member along the linear modified region, and UV rayirradiation means which irradiate the tape with UV rays.

According to the present invention, the tape is irradiated with UV rays(light in the wavelength region of ultraviolet rays) during expanding.By irradiation with UV rays, it is possible to cure an adhesive of thetape and to change the adhesion of the tape and, therefore, theelongation of the tape can be made uniform all over the surface of theplate-like member when the tape is elongated by applying a tensionthereto. As a result, it is possible to positively manufacture anultrathin chip with a good end-face shape in which uncut portions,chipping and breakage do not occur when multiple substrates are obtainedby dividing the plate-like member along the linear modified region.

Also, according to the present invention, it is necessary only that UVray irradiation means be added to a conventional device for dividing aplate-like member, and the construction of the apparatus can be madesimple. The dividing work of a plate-like member becomes also simple. Asa result, it becomes possible to miniaturize the apparatus for dividinga plate-like member and the dividing work of a plate-like member can beperformed in a short time.

Incidentally, the linear modified region is not necessarily be acontinuous linear one and may be in the form of a broken line such as adotted line. This is because even in such a broken linear modifiedregion, it is possible to positively manufacture an ultrathin substratewith a good end-face shape in the same way as in a continuous linearmodified region.

In the present invention, it is preferred that in the expanding step,the tape be irradiated with UV rays in a pattern by use of a photomask.This is because if the tape is irradiated with UV rays in a pattern likethis, by discriminating between the tape in a portion corresponding tothe linear modified region of the plate-like member and the tape inother portions, the adhesion of the tape is changed and the curedcondition of the adhesive of the tape is changed, whereby the area nearthe modified region of the plate-like member is selectively expanded andthe expanding force of the tape can be efficiently transmitted as adividing force to the plate-like member, with the result that the objectof the present invention that an ultrathin substrate with a goodend-face shape is positively manufactured is more easily achieved.Incidentally, in the present invention, a “pattern” refers to a specificpattern which is made on the basis of the size and shape of individualsubstrates obtained by the dividing of the plate-like member, and anaggregate or array of the specific pattern and which is used toselectively irradiate the tape with UV rays.

In the present invention, it is preferred that in the modified regionforming step, the modified region be formed on the surface of theplate-like member or in the interior thereof by causing laser beams tobecome incident on the plate-like member. This is because the use oflaser beams can exhibit superiority in various aspects such asproductivity, running cost and quality although methods like dicing,scribing, etc. can be adopted in forming the liner modified region onthe surface of the plate-like member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart which shows the flow of the first embodiment of amethod for dividing a plate-like member related to the presentinvention;

FIG. 2 is a conceptual diagram to explain a laser dicing device;

FIG. 3 is a conceptual diagram to explain the principle of a method fordividing a plate-like member related to the present invention;

FIG. 4 is a sectional view which shows an outline of the firstembodiment of a method for dividing a plate-like member related to thepresent invention;

FIG. 5 is a conceptual diagram which shows an outline of the secondembodiment of a method for dividing a plate-like member related to thepresent invention;

FIG. 6 is a conceptual diagram which shows an outline of the thirdembodiment of a method for dividing a plate-like member related to thepresent invention;

FIG. 7 is a flowchart which shows the flow of a conventional method fordividing a plate-like member;

FIG. 8 is a conceptual diagram to explain a conventional expanding step;and

FIGS. 9(a) and 9(b) are each a schematic diagram to explain the divisionof a wafer in a conventional expand step.

BEST MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of a method and an apparatus for dividing aplate-like member related to the present invention will be describedbelow with reference to the accompanying drawings.

FIG. 1 is a flowchart which shows the flow of the first embodiment of amethod for dividing a plate-like member related to the presentinvention. In this first embodiment, first, the back surface side of awafer on the front surface side of which many IC circuits are formed isplaced on a table, and subsequently, a ring-shaped dicing frame isdisposed outside the wafer. Subsequently, a dicing tape having anultraviolet (hereinafter referred to as UV) curing type adhesive on onesurface is stuck from above to the frame and the front surface of thewafer, and the wafer is mounted on the frame (Step S11). In thiscondition, the front surface of the wafer is protected by the dicingtape, and at the same time, the front surface is integrated with theframe, resulting in good transportability (the above descriptioncorresponds to the tape sticking step).

Next, the back surface of the wafer is ground by a back grinder to athickness close to a specified thickness (for example, 50 μm). After thegrinding, a work-affected layer generated during grinding is removed bypolishing. The back grinder used here is a polish grinder having thefunction of polishing and can remove the work-modified layer simply bypolishing without releasing the adsorption of the wafer after grinding.Therefore, even when the thickness of the wafer is 30 μm or so, thewafer will not be broken. The wafer thus polished is cleaned and driedby a cleaning and drying device provided in the back grounder (StepS13).

Next, the wafer thus worked to a specified thickness is diced by a laserdicing built in the polish grinder having the function of polishing soas to be divided into individual chips. The wafer, along with the frame,is adsorbed by the table and laser beams are caused to become incidentfrom the front surface side of the wafer via the dicing tape. Because acondensing point of the laser beams is set in the interior of the waferin the thickness direction of the wafer, the laser beams which havetransmitted the front surface of the wafer are such that the energy isconcentrated on the condensing point in the interior of the wafer and amodified region by multiphoton absorption is formed in the interior ofthe wafer (the above description corresponds to the modified regionforming step). As a result of this, the balance of an intermolecularforce in the wafer is disrupted and the wafer becomes naturally cut orbecomes cut by a slight outer force (Step S15).

FIG. 2 is a conceptual diagram to explain a laser dicing device built ina polish grinder. As shown in FIG. 2, in the laser dicing apparatus 10,an XYZ θ ?table 12 is provided on a machine base 11, and the XYZ θ table12 on which a wafer W is adsorbed and loaded is precisely moved in theXYZ θ direction. An optical system 13 for dicing is provided on a holder14, which is similarly provided on the machine base 11.

The optical system 13 is provided with a laser beam source 13A, andlaser beams oscillated from the laser beam source 13A are condensed inthe interior of the wafer W via the optical system of a collimate lens,a mirror, a condenser lens, etc. Laser beams used here have transmissioncharacteristics for a dicing tape under the conditions: the peak powerdensity at the condensing point is not less than 1×10⁸ (W/cm²) and thepulse width is not more than 1 μs. Incidentally, the position of thecondensing point in the thickness direction is adjusted by themicromotion of the XYZ θ table 12 in the Z-direction.

The laser dicing device 10 is provided with an observational opticalsystem, which is not shown, and the alignment of the wafer is performedon the basis of a pattern formed on the front surface of the wafer,whereby the incident position of laser beams is determined. After thecompletion of the alignment, the XYZ θ table 12 moves in theXY-direction and laser beams are caused to become incident along adicing street of the wafer.

After the laser dicing in Step S15 shown in FIG. 1, the expanding stepis performed which involves radially expanding the dicing tape andwidening the gap between chips (Step S17). Details of this step will begiven later.

With the dicing tape expanded, UV rays are radiated from the dicing tapeside, whereby the adhesive of the dicing tape is cured and its adhesionis reduced. Incidentally, this irradiation with UV rays may be performedat the end of the dicing step.

Subsequently, one chip in an expanded condition is pushed up from thedicing tape side and exfoliated from the dicing tape, this chip issucked by a pickup head and sucked by a collet for chip mounting, withthe front and back surfaces reversed, and the chip is mounted on apackage substrate, such as a lead frame (Step S19). After the chipmounting step, the packaging step of wire bonding, molding, leadtrimming and forming, marking, etc. is performed and an IC is completed.The foregoing is an outline of the first embodiment.

Next, details of the expanding step will be given. FIG. 3 is aconceptual diagram to explain the principle of a method for dividing aplate-like member related to the present invention, and FIG. 4 is asectional view which shows an outline of the first embodiment.

As shown in FIG. 3, a modified region K formed by laser beams is presentin the interior of a wafer W. As shown in FIG. 3, the tension applied tothe wafer W on both sides of the modified region K via the dicing tape Sis indicted by arrows in the right and left directions. As indicated bymultiple upward arrows, UV rays are radiated from the bottom surface ofthe dicing tape S to almost the whole surface of the dicing tape S.

FIG. 4 shows a dividing device 20 for performing this dividing method.As shown in FIG. 4 and FIG. 8, which was described above, the peripheraledge portion of the dicing tape S is fixed to the frame F. A ring member22 abuts against the bottom surface of the inner portion of theperipheral edge portion of the dicing tape S. The top peripheral portionof this ring member 22 is rounded smooth. Below the dicing tape S, thereis disposed a UV ray source 24 (UV ray irradiation means).

UV rays are radiated from the UV ray source 24 at the dicing tape S and,at the same time, the frame F is pushed down in the direction of thearrows of FIG. 4. By radiating UV rays, it is possible to cure theadhesive of the dicing tape S and change the adhesion of the tape.

Simultaneously, a force indicated by the arrows of the figure is appliedto the frame F, and the frame is pushed down. As a result of this, thedicing tape S is expanded and the gap between chips T is widened. Atthis time, because the top peripheral edge portion of the ring member 22is rounded smooth, the dicing tape S is smoothly expanded.

It is possible to adopt publicly known direct-operated devices ofvarious types as a mechanism for pushing down the frame F. For example,it is possible to adopt a direct-operated device which is constituted bycylinder members (by hydraulic pressure, pneumatic pressure, etc.), amotor and screws (a male screw as a shaft and a female screw as abearing).

For the irradiation conditions with UV rays, such as irradiationcapacity (electric power), wavelength range and irradiation time,appropriate values can be selected according to the material quality ofthe adhesive of the dicing tape S, the size of the wafer W and the sizeof chips T after cutting.

According to the first embodiment described above, in the expandingstep, owing to the irradiation with UV rays, it is possible to cure theadhesive of the dicing tape S and to change the adhesion of the dicingtape S and, therefore, the elongation of the dicing tape S can beperformed uniformly all over the surface of the wafer W. As a result ofthis, it is possible to manufacture an ultrathin chip with a goodend-face shape in which uncut portions, chipping and breakage do notoccur when chips T are obtained by dividing the wafer W along themodified region K.

Next, the second embodiment of the present invention will be describedon the basis of FIG. 5. This second embodiment differs from theabove-described first embodiment only in the expanding step. Therefore,detailed descriptions of other common steps are omitted.

In the construction shown in FIG. 5, a photomask M is disposed at thebottom surface of the dicing tape S in addition to the arrangement ofthe first embodiment. Because other parts are the same as the dividingapparatus 20 shown in FIG. 4, the illustration of this dividingapparatus 20 and detailed descriptions of each part of this dividingapparatus 20 are omitted.

It is possible to adopt, as the photomask M, various kinds of photomaskssuch as glass masks (made of synthetic quartz, low-thermal-expansionglass, soda lime glass, etc.), film masks (made of a polyester filmetc.), and metal masks according to accuracy, cost, etc.

In the construction shown in FIG. 5, the photomask M is arranged in sucha manner that square-shaped light shielding portions M1 cover the middlepart of each of divided chips T when the photomask M is plan-viewed.That is, the arrangement is such that portions of the dicing tape Scorresponding to the peripheral edge portion of each of the chips Twhich are divided are irradiated with UV rays which have transmitted thelight shielding portions M2 of the photomask M. In this case, as shownin the figure, the adhesive of the dicing tape S in these portionsbecome irradiated portions 30.

UV rays are radiated from the UV ray source 24 (refer to FIG. 4) at thedicing tape S via the photomask M and, at the same time, the frame F ispushed down (refer to FIG. 4). Due to the irradiation with the UV rays,the adhesion of the irradiated portion 30 of the dicing tape Sdecreases.

Simultaneously, the dicing tape S is expanded and the gap between chipsT is widened. At this time, because the dicing tape S corresponding tothe peripheral edge portion of each of the chips T is the irradiatedportion 30 and the adhesion of the adhesive in this portion decreases,the dicing tape S near portions of chips T which are to be cut isselectively expanded. That is, the expanding force of the dicing tape Sis efficiently transmitted as a dividing force to the wafer W. As aresult of this, the dividing of the chips T can be performed all overthe surface of the wafer W without generating uncut portions when chipsT are obtained by dividing the wafer W along the modified region K.

For the irradiation conditions with UV rays, such as irradiationcapacity (electric power), wavelength range and irradiation time,appropriate values can be selected according to the material quality ofthe adhesive of the dicing tape S, the size of the wafer W and the sizeof chips T after cutting.

According to the above-described second embodiment, in the expandingstep, due to the irradiation with the UV rays through the photomask M,the adhesion of the dicing tape S can be selectively reduced in theirradiated portion 30 and the expanding force of the dicing tape S canbe efficiently transmitted as a dividing force to the wafer W all overthe surface of the wafer W. As a result of this, it is possible tomanufacture an ultrathin chip with a good end-face shape in which uncutportions, chipping and breakage do not occur when chips T are obtainedby dividing the wafer W along the linear modified region K.

Incidentally, in the second embodiment, it is also possible to use adicing tape S of high adhesion.

Next, the third embodiment related to the present invention will bedescribed on the basis of FIG. 6. This third embodiment differs from theabove-described first and second embodiments only in the expanding step.Therefore, detailed descriptions of other common steps are omitted.

In the construction shown in FIG. 6, a photomask M is disposed at thebottom surface of the dicing tape S in addition to the arrangement ofthe first embodiment. Because other parts are the same as the dividingapparatus 20 shown in FIG. 4, the illustration of this dividingapparatus 20 and detailed descriptions of each part of this dividingapparatus 20 are omitted.

In the same way as in the second embodiment it is possible to adopt, asthe photomask M, various kinds of photomasks such as glass masks (madeof synthetic quartz, low-thermal-expansion glass, soda lime glass,etc.), film masks (made of a polyester film etc.), and metal masksaccording to accuracy, cost, etc.

In the construction shown in FIG. 6, the photomask M is arranged in sucha manner that frame-like light shielding portions M1 cover theperipheral edge portion of each of divided chips T when the photomask Mis plan-viewed. That is, the arrangement is such that portions of thedicing tape S corresponding to the center part of each of the chips T tobe divided are irradiated with UV rays which have transmitted the lightshielding portions M2 of the photomask M. In this case, as shown in thefigure, the adhesive of the dicing tape S in these portions becomeirradiated portions 40.

UV rays are radiated from the UV ray source 24 (refer to FIG. 4) at thedicing tape S via the photomask M and, at the same time, the frame F ispushed down (refer to FIG. 4). Due to the irradiation with the UV rays,the curing of the irradiated portion 40 of the dicing tape S ispromoted.

Simultaneously, the dicing tape S is expanded and the gap between chipsT is widened. At this time, because the dicing tape S corresponding tothe center part of each of the chips T is the irradiated portion 40 andthe curing of this portion is promoted, the dicing tape S of thisportion tends to be less expanded and the dicing tape S near portions ofchips T which are to be cut is selectively expanded, these portionsbeing portions other than the irradiated portion 40. That is, theexpanding force of the dicing tape S is efficiently transmitted as adividing force to the wafer W. As a result of this, in dividing thewafer W, the dividing of the chips T can be performed all over thesurface of the wafer W without generating uncut portions.

For the irradiation conditions with UV rays, such as irradiationcapacity (electric power), wavelength range and irradiation time,appropriate values can be selected according to the material quality ofthe adhesive of the dicing tape S, the size of the wafer W and the sizeof chips T after cutting.

According to the above-described third embodiment, in the expandingstep, due to the irradiation with the UV rays through the photomask M,the curing of the dicing tape S can be selectively promoted in theirradiated portion 40 and the expanding force of the dicing tape S canbe efficiently transmitted as a dividing force to the wafer W all overthe surface of the wafer W. As a result of this, it is possible tomanufacture an ultrathin chip with a good end-face shape in which uncutportions, chipping and breakage do not occur when the wafer W is dividedalong the modified region K to obtain each chip. Furthermore, accordingto the third embodiment, the advantage that the exfoliation of chips Tdoes not easily occur in the expanding step is also obtained.

Although embodiments of a method and an apparatus for dividing aplate-like member related to the present invention have been describedabove, the present invention is not limited to the above-describedembodiments and it is possible to adopt various modes.

For example, in the examples of the embodiments, a laser dicing deviceis used in the modified region forming step in which a modified regionis formed on the surface of a wafer W to which a dicing tape S is stuckor in the interior of the wafer W. However, in the modified regionforming step, a modified region may be formed by using other devices,for example, a dicing saw.

Also, in the examples of the embodiments, the descriptions were given ofa case where a plate-like member formed from a hard and brittle materialis used in the wafer W. However, the dividing method and dividingapparatus of a plate-like member of the present invention can also beapplied to the dividing of other various kinds of hard and brittlematerials, for example, glass substrates used in various kinds ofdisplay elements (LC, EL, etc.). In the dividing of such glasssubstrates by scribing, the occurrence of flaws due to the formation ofglass chips was a big problem. In the present invention, however, it ispossible to effectively cope with this problem.

In the examples of the embodiments, the descriptions were given of anexample in which ultrathin chips are obtained by working an ultrathinwafer having a thickness of 30 μm to 100 μm or so. However, the methodof dividing a plate-like member of the present invention can also beapplied to chips of not less than 100 μm.

INDUSTRIAL APPLICABILITY

As described above, according to the present invention, in the expandingstep, tape is irradiated with UV rays (light in the wavelength range ofultraviolet rays). As a result of this, it is possible to cure theadhesive of the tape and to change the adhesion of the tape and theelongation of the dicing tape S can be made uniform all over the surfaceof the wafer W. As a result of this, it is possible to positivelymanufacture an ultrathin chip with a good end-face shape in which uncutportions, chipping and breakage do not occur when multiple substratesare obtained by dividing the plate-like member along the linear modifiedregion.

Also, according to the present invention, it is necessary only that UVray irradiation means be added to a conventional device for dividing aplate-like member, and the construction of the apparatus can be madesimple. The dividing work of a plate-like member becomes also simple. Asa result, it becomes possible to miniaturize the apparatus for dividinga plate-like member and the dividing work of a plate-like member can beperformed in a short time.

1. A method for dividing a plate-like member formed from a hard andbrittle material, comprising a steps of: sticking tape on a surface ofthe plate-like member; forming a linear modified region on the surfaceof the plate-like member to which the tape has been stuck or in theinterior thereof; and elongating the tape by applying a tension theretoafter forming the linear modified region and irradiating the tape withUV rays, whereby the plate-like member is divided along the linearmodified region thereby to obtain multiple substrates.
 2. The method fordividing a plate-like member according to claim 1, wherein in the stepof elongating the tape, the tape is irradiated with UV beams in apattern by use of a photomask.
 3. The method for dividing a plate-likemember according to claim 1, wherein in the step of forming a linearmodified region, the modified region is formed on the surface of theplate-like member or in the interior thereof by causing laser beams tobecome incident on the plate-like member.
 4. The method for dividing aplate-like member according to claim 2, wherein in the step of forming alinear modified region, the modified region is formed on the surface ofthe plate-like member or in the interior thereof by causing laser beamsto become incident on the plate-like member.
 5. An apparatus fordividing a plate-like member which is formed from a hard and brittlematerial and to the surface of which tape is stuck and a liner modifiedregion is formed on the surface of which or in the interior of whichalong the liner modified region to obtain several substrates,comprising: an expand device which applies a tension to the tape andelongates the tape in order to divide the plate-like member along thelinear modified region; and a UV ray irradiation device which irradiatesthe tape with UV rays.